There is a quite interesting story behind ma Annapurna and quite a reality of every household where cooking and serving food.. the main essence of sustenance of life energy is taken as a mere work and ridiculed.

Lord shiva once immersed in yog Nidra didnot return to kailasha for a long time.. when he returned.. he was again busy with his ganas and enjoyed his pleasure time.. when he went to meet ma parvati… who was infuriated with his such behaviour tried to make him understand that how much energy does it take to run a household where all different ganas of shiva, nagas, auras, suras all roamed around and timely came to the mother goddess for food.. I.e Anna. But as usual.. when does this would have easily been understood by the masculine energies.. instead Lord Shiva laughed off and ridiculed Ma parvati’s pain and stated it as a mere small work because Lord shiva on the other hand was teaching the world of renunciation of worldly desires like food.. and getting involved in Yog

So Ma parvati thought to teach a lesson and disappeared from kailasha and shiv samsara

As a result every body went starving in the entire world..

Lord shiva too hungry and missing ma Parvati’s food went for searching her and found that the entire world and found a long queue in Kashi.. so lord Vishwanath came Kashi to learn that there is a Maa who is serving food for all.. he knew this is no one else but his dear wife.. who loves to cook food and serve it to her children.. so lord shiva tried to hack the queue but was pulled back

He waited while starving and when he came near to ma for bhiksha he said the above mantra :

अन्नपूर्णे सदापूर्णे शंकर प्राणवल्लभे ।

ज्ञान वैराग्य सिध्यर्थं भिक्षां देहिच पार्वति ॥

माता च पार्वती देवी पिता देवो महेश्वरः ।

बान्धवाः शिवभक्ताश्च स्वदेशो भुवनत्रयम् ॥

annapūrṇe sadāpūrṇe śaṃkara prāṇavallabhe .
jñāna vairāgya sidhyarthaṃ bhikṣāṃ dehica pārvati ..
mātā ca pārvatī devī pitā devo maheśvaraḥ ..
bāndhavāḥ śivabhaktāśca svadeśo bhuvanatrayam ॥

Mata Annapurna mandir in Kashi is a only temple where every devotee is served food before the food is served to the mother goddess.

There is also a very famous proverb: Kashi me koi bhukha nhi sota. And it is truth.